Drug interactions
Mexiletine + Olanzapine / samidorphan
Severity: Moderate
Mexiletine and Olanzapine / samidorphan: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Mexiletine is a potent CYP1A2 inhibitor and olanzapine is cleared largely by CYP1A2. Olanzapine levels may rise, increasing sedation, orthostatic hypotension and anticholinergic effects.
What this interaction means in plain words
Mexiletine and Olanzapine / samidorphan can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Mexiletine inhibits CYP1A2-mediated metabolism of olanzapine.
What to do
Monitor for sedation, hypotension and tachycardia and consider a lower olanzapine dose when starting mexiletine.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Mexiletine
- Fezolinetant + Mexiletine Contraindicated
- Mexiletine + Pimozide Contraindicated
- Alosetron + Mexiletine Major
- Amiodarone + Mexiletine Major
- Clozapine + Mexiletine Major
- Cobicistat + Mexiletine Major
Frequently asked questions
Can I take Mexiletine with Olanzapine / samidorphan?
MediHelp rates the interaction as moderate. Mexiletine and Olanzapine / samidorphan can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Mexiletine is a potent CYP1A2 inhibitor and olanzapine is cleared largely by CYP1A2. Olanzapine levels may rise, increasing sedation, orthostatic hypotension and anticholinergic effects.
How serious is the interaction between Mexiletine and Olanzapine / samidorphan?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for sedation, hypotension and tachycardia and consider a lower olanzapine dose when starting mexiletine.
What other medicines interact with Mexiletine?
MediHelp also lists interactions of Mexiletine with, for example, Fezolinetant, Pimozide, Alosetron. The full list is on the Mexiletine page.
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